Counterfeit-proof metallic foil

ABSTRACT

A counterfeit-proof metal foil is textured in at least a given partial area of its surface, this partial area having a radiation refraction value which is different compared to the remaining surface area. The metal foil is suitable as a packaging material, among others for medications. The manufacturer or the consumer can check based on the given surface structure which is intended as an identification sign whether he has acquired an uncounterfeited product. If texturing takes place on most of the surface of the metal foil, this is identical to the appearance of a printed picture so that the metal foil as claimed in the invention is likewise used as a decorative foil or an advertizing medium.

[0001] The invention relates to a counterfeit-proof metal foil, aprocess for its production and its use for producing packaging material,decorative foils and advertizing media.

PRIOR ART

[0002] The demand for counterfeit-proof packaging material, for examplefor medications, has grown in recent years to the extent the amount ofcounterfeit medications has risen relatively greatly worldwide. Thesecounterfeits can be pharmaceutically active drugs, but also agents witha placebo effect.

[0003] Therefore the attempt is made, as is known in banknotes, toprovide packaging materials for the pharmaceutical industry withholograms. It has been found that even holograms, although theirproduction is relatively complicated, can be counterfeited withincreasing technical development. These counterfeits can only becharacterized or recognized as such by a specialist since it isdifficult for the user of a medication to ascertain whether the hologramis counterfeit or not if he does not have the corresponding comparisonspecimen.

[0004] Regardless of this, the attempt is made to producecounterfeit-proof packaging material in so far as the material surfaceis provided with a special coating which has pigments which can beactivated by radiation. Thus, for example, the company logo of themanufacturer or the trademark of the medication can be made visible orinvisible by radiation, such as UV or IR rays. EP-A2-1 217 091 relatesto packaging with an integrated initial opening and/or originalityguarantee which is produced by a coating which reflects incident lightso that depending on the direction or angle of viewing different colorsare discerned.

[0005] EP-A1-0 967 091 describes a coating of several grid images whichare matched to one another and which, depending on the viewing angle,produce a different optical perception. But it has been found that thesecoating systems can also be added so that satisfactorycounterfeit-proofness, especially with respect to packaging materialsfor the pharmaceutical industry, could not be achieved in this way.

DESCRIPTION OF THE INVENTION

[0006] The object of this invention is to avoid these known defects ofallegedly counterfeit-proof metal foils.

[0007] This object is achieved as claimed in the invention using a metalfoil which is characterized in that it is textured in at least a givenpartial area of its surface and that this partial area has lightdiffraction, scattering, refraction or reflection which differs comparedto the remaining surface area. Further embodiments of thecounterfeit-proof metal foil as claimed in the invention are disclosedaccording to the dependent claims.

[0008] The invention relates to a process for producing thiscounterfeit-proof metal foil, the textured partial areas being producedby means of laser technology.

[0009] The invention relates furthermore to a process for producing thiscounterfeit-proof metal foil, its being produced as claimed in theinvention during a rolling process and at least one of the working rollsused having a surface which is textured in at least a given partialarea, so that in the rolling process the structure of the roll surfaceis transferred to the metal foil. Other embodiments of this process asclaimed in the invention are disclosed according to the dependentclaims.

[0010] The invention relates furthermore to the use of thecounterfeit-proof metal foil as claimed in the invention for producingpackaging material, for example for medications, decorative foils andadvertizing media.

DESCRIPTION OF THE INVENTION USING DRAWING AND EMBODIMENTS

[0011] The invention is detailed below using FIGS. 1 to 3.

[0012]FIGS. 1 and 2 show an extract from the counterfeit-proof metalfoil 1 as claimed in the invention; and

[0013]FIG. 3 shows a device in the form of a rolling mill 6 forproducing the metal foil 1 as claimed in the invention.

[0014] One possible approach to implementing the invention is detailedbelow.

[0015] The starting product for producing the metal foil as claimed inthe invention, for example, aluminum foil 1′, is supplied to a rollingmill 6. It consists of backing rolls 7 and working rolls 8. The startingproduct in the form of a metal foil 1′ is supplied to the roll gapbetween the working rolls 8 from a storage roll, specifically anuncoiling reel 9, via deflector rollers 11. The thickness of the foilused is reduced by the pressure of the working rollers which is used.Thus, for example, an aluminum foil 1′ with an initial thickness of 40microns can be reduced to 20 microns in one rolling process. Theattained thickness of the foil is monitored at the measurement station12, the foil 1 consequently being supplied to a winding reel, thereforeanother bearing roll 10. This rolling process can be repeated severaltimes depending on the desired thickness.

[0016] In order to achieve the surface texturing as claimed in theinvention, in the last rolling process the working roll pair is replacedby another working roll pair 8 which on its surface has texturingcorresponding to one or more partial areas, as is to be achieved in thecounterfeit-proof foil 1 as claimed in the invention. This texturing canbe produced for example by grinding, polishing, etching, laser treatmentor engraving of the surface of the working roll, laser technologyproving especially preferable. Thus the texturing can be varied in awide range so that on the one hand texturing visible to the viewer andon the other hand invisible texturing are produced.

[0017] Visible texturing of the roll surface produces likewise visibletexturing on the surface of the metal foil, conversely the invisibletexturing enables so-called hidden counterfeit-proof texturing. Duringthe rolling process the indicated texturing is transferred using therequired deformation pressure to the metal foil which thus as claimed inthe invention has this texturing in at least one given partial area ofits surface. The texturing can of course also extend to most of the rollsurface so that not only counterfeit-proof, but at the same time acorrespondingly decorated foil is produced.

[0018] Texturing can be regular, therefore with a geometricalarrangement, or random, for example rippled lines.

[0019] Depending on the application, the two surface sides of the metalfoil can also be textured, for which the two working rolls 8 must bemade accordingly with texturing.

[0020] Of course it is also possible to produce the textured surfaceareas on the counterfeit-proof metal foil 1 independently of the rollingprocess. Laser technology is suitable for this purpose, by which,depending on the extent of irradiation, both hidden surface texturing,i.e. not visible with the naked eye, and also surface texturing visibleto the naked eye can be produced.

[0021] The invention is detailed using one embodiment of the metal foil1 as claimed in the invention, as is described for example in FIGS. 1 to2.

[0022] Here, as shown in FIG. 1, surface texturing in the form of aplanar identification sign 2, specifically a company logo, isreproduced. It differs in its radiation refraction value from theremaining foil surface 3 and is sometimes detectable to the viewer withthe naked eye. If the company logo is one which is known to the vieweras the manufacturer for the packaging material, he has to have thecertainty of obtaining an uncounterfeited product.

[0023] Depending on the surface texturing, the corresponding refractionor scattering of the incident light takes place. It can be measured forexample using the reflection pattern which has formed. Thismeasurability is especially important when the surface texturing cannotbe detected with the naked eye.

[0024] Another identification sign is disclosed according to FIG. 2.Since the metal foils as claimed in the invention are preferablyproduced by a rolling process, by which, especially in the direction ofrunning, the structure S of the roll surface, which structure is pointedlengthwise, is transferred to the surface of the metal foil 1, forexample, by grinding the roll surface, texturing in the transversedirection to the direction of running can be produced such that atextured partial area 4 results on the metal foil 1 which causes achange in the light refraction. If the given texturing in the partialarea 4 is compared to a pattern or to the roll surface, in case ofagreement it can be precluded that it is a counterfeit product.

[0025] The pattern which has formed can be arranged regularly, but alsorandomly. Thus an irregularly arranged pattern is therefore associatedwith high counterfeit-proofness, since the texturing which has beenformed using the random principle is known solely to the manufacturer.For test purposes, as is necessary in the packaging of medications, themanufacturer can check that the texturing on the surface of thepackaging material is identical to that on the roll surface or on thecorresponding patterns of the metal foil 1 using random samples ofpackaging material.

[0026] Furthermore, after producing the foil as claimed in theinvention, the surface texturing can also be determined by a comparativeoptical measurement. This takes place for example with conventionallight reflection measurement instruments.

[0027] The metal foils as claimed in the invention can be provided witha transparent coating after their surface texturing. Printing inkmixtures and plastic laminations which can optionally have pigments aresuitable as transparent coatings. For example polyethylene terephthalate(PET), oriented polyamide (oPA) and laminations of orientedpolypropylene (oPP) are suitable as plastic laminations.

[0028] These transparent coatings increase the decorative effect so thatthe metal foil as claimed in the invention is also used as a decorativefoil or as advertizing media.

[0029] The identification sign in the form of surface texturing canhowever also be made invisible first by a covering enamel so that it isonly made visible to a specialist upon further use. Using the comparisonsamples he checks whether it is an uncounterfeited product or not.

[0030] Commercial Applicability

[0031] The metal foils as claimed in the invention are used forproducing packaging material, their being especially suited as packagingmaterial for medications. In this use the manufacturer or the consumercan easily ascertain based on the given texturing in the foil surfacethat he has acquired an uncounterfeited product so that there iscounterfeit-proofness based on the metal foil as claimed in theinvention.

[0032] If texturing takes place on most of the surface of the metalfoil, this is identical to the appearance of a printed picture so thatthe metal foil as claimed in the invention is likewise used as adecorative foil or an advertising medium.

1. Counterfeit-proof metal foil (1), characterized in that the metalfoil is textured in at least a given partial area (2, 4) of its surfaceand that this partial area has light diffraction, scattering, refractionor reflection which differs compared to the remaining surface area (3,5).
 2. Counterfeit-proof metal foil as claimed in claim 1, wherein themetal foil consists of aluminum.
 3. Counterfeit-proof metal foil asclaimed in claim 1, wherein the metal foil as a textured partial area(2) has a planar identification sign.
 4. Counterfeit-proof metal foil asclaimed in claim 1, wherein the given partial area (4) has a linearstructure.
 5. Counterfeit-proof metal foil as claimed in claim 4,wherein the linear structure is arranged geometrically or randomly. 6.Counterfeit-proof metal foil as claimed in claim 1, wherein there aretextured partial areas (2, 4) on the two surface sides of the metalfoil.
 7. Counterfeit-proof metal foil as claimed in claim 1, whereinthere are structured partial areas (2, 4) on almost the entire surface.8. Counterfeit-proof metal foil as claimed in claim 1, wherein most ofthe textured partial areas (2, 4) are visible to the viewer, theremainder is invisible to the viewer.
 9. Counterfeit-proof metal foil asclaimed in claim 1, wherein the surface of the metal foil which isprovided with textured partial areas is provided with a transparentcoating.
 10. Counterfeit-proof metal foil as claimed in claim 9, whereinthe transparent coating contains printing inks and/or plastic andoptionally additives.
 11. Process for producing a counterfeit-proofmetal foil as claimed in claim 1, wherein the textured partial areas (2,4) are produced by means of laser technology.
 12. Process for producinga counterfeit-proof metal foil as claimed in claim 1, wherein the metalfoil is produced by means of work rolls 8, at least one work roll beingtextured on its surface in at least one partial area, and wherein thisstructure is transferred to the metal foil during the rolling process.13. Process as claimed in claim 12, wherein the surface of the twoworking rolls (8) is textured.
 14. Process as claimed in claim 12,wherein almost the entire roll surface is textured.
 15. Process asclaimed in claim 12, wherein most of the texturing on the roll surfaceis visible to the viewer, but the remainder is not visible to theviewer.
 16. Process as claimed in claim 12, wherein the metal foil aftertexturing is provided with a transparent coating.
 17. Process as claimedin claim 16, wherein the transparent coating contains printing inksand/or plastic and optionally additives.
 18. Process as claimed in claim12, wherein the given, textured partial areas on the roll surface areproduced using laser technology.
 19. Use of a counterfeit-proof metalfoil as claimed in claim 1 for producing packaging material.
 20. Use ofa counterfeit-proof metal foil as claimed in claim 1 for producingdecorative foils.
 21. Use of a counterfeit-proof metal foil as claimedin claim 1 for producing advertizing media.